Telephone-receiver.



Patented mar. 2s, |904.

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TELEPHUNE RECEIVER. (Applxcatxon led Sept B 1899 (No Modul.)

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VNrrED STATES "AIENT ENCE.

CHARLES H. NORTH, OF CLEVELAND, OHIO, ASSIGNOR TO THE NORTH ELECTRICCOMPANY, OF SAME PLACE.

TELEPHONE-Receives.

SPECIFICATION forming part of Letters Patent No. 670,564, dated Meren2e, 1901'.

Application filed September 27, 1899. Serial No. '781,798- (No model.)

T a/ZZ when?, t may concern.-

Be it known that LOHAELES H. NORTH, a citizen of thenited States,residing at Cleveland, in the county of Cuyahoga and State of Ohio,haveinvented a certain new and useful Improvement in TelephoneReceivers, .of which the following is a full, clear, andexactdescription, reference being had to the accompanying drawings.

The object of my invention is to provide a telephone receiver, whichwhile being simple and cheap in construction,shall, first, minimize thedisadvantages resulting from the different rates of expansion of thematerial comprising the receiver; second, shall be convenientlyadjustable to regulate the distance between the magnet-poles and thediaphragm, and, third, shall have no exposed binding-posts. l l

The invention consists in the means I employ for attaining these ends ormaterial parts thereof, as hereinafter specified, and

definitely set out in the claims.

The drawings clearly disclose my invention.

Figure 1 is avertical central section of the receiver complete. Fig. 2is a side elevation of the interior of the receiver, and Fig. 3 is avertical central section at right angles to Fig. 2. Fig. 4. is aperspective View of the electromagnets and the brass block which holdsthem in place. Figs. 5 and 6 are horizontal sections, respectively, onthe lines 5 5 and 6 6 of Fig. 2. Fig. 7 is a top view of the interior ofthe receiver, the diaphragm being partly broken away.

Referring to the parts by letters, A represents the body of the casing,preferably made of hard rubber, and B the cap therefor, which screwsonto the outside of the body by the internal threads b.

C represents a frame which is preferably a brass cup or cone-frustumhaving a flange c taking over the upper end of the body A. This flangehas external threads c', which mesh with the threads b on the cap B.Extending across the mouth of` the cup, between it and the cap, isthe'diaphragm D.

The permanent magnet is preferably a single horseshoe-magnet, or, ifdesired, two inform of a mutilated cylinder having two opposite sideswhich are screw-threaded, as at g, but between them being recessed, asat g. The recessed part lies between the bars E E, while thescrew-threaded part projects over beyond the edges thereof. A screw-boltII clamps the block, the electromagnets, and

the permanent magnet all together by screwing through one barE andthrough the intermediate parts into the other bar. The cup C screws ontothe block G by reason ofthe threads g thereon and internal threads on aflange c2, depending from the cup. A pair of jam-nuts J and J' alsoscrew onto the block G and lock each other and the cup C. This method ofsupporting the magnet reduces to a minimum the disarrangement of theparts by unequal expansion or contraction. The difference in expansionbetween the cores F and the cup C (these being the parts which arefactors in the`result) is insignificant, while if the magnet weresupported at its lower end by the rubber casing, as has been customary,the dierent rates of expansion between the steel and rubber aresufficient to be very annoying.

The receiver is easily adj usted to the point of greatest efficiency.The casing A is unscrewed from the cap B, and the jam-nuts J and Jloosened, and the cup C turned in one direction .or the other, asrequired, (thus moving the diaphragm toward or from the magnet-poles,)and is then locked by the j am-nuts. Since the cup C is screw-threadedto the cap, the removal of the casing A does not in the least interferewith the electric operation of the receiver, and the latter lnay thus beadjusted by sound, which is much more aecurate than by measurement.V

By making the external diameter of the cup C the same as that of thehead of the casing A the thread b on the cap is made continuous, whichis not only the simplest and cheap- IOO est form, but allows the casingA to abut against the flange c of the cup, and thus act as a jam-nut forit.

The ends of the coilf of the electromagnets are secured to insulatedwires K, which pass down through a pair of longitudinal holes g2 in theblock. G. At their lower ends these wires are secured by screws L (whichtake into an insulating-block M, held between the bars E) to the twoends of the flexible cord N. In order to prevent a sudden shock on thecord from pulling it loose from the screws or from dslocating thelatter, the two ends of the cord cross over from one side of the blockonto the other through the opening 'm therein. The two ends cometogether beneath the magnet and pass out of the casing through theopening a as one cord.

By making the connection with the flexible cord entirely within thecasing a very neat appearance is given to the receiver, and, moreover,the possibility of a shock from an accidental contact with exposedbinding-posts or the accidental disconnection of the cord therefrom isobviated.

I claim- 1. In a telephone-receiver, in combination, a casing-body, acap secured to the same, a cup within the casing having a projectionextending between the cap and body, a diaphragm between the cup and cap,and a magnet carried by said cup and adjustable with reference thereto,substantially as described.

2. In a telephone receiver, a horseshoemagnet, a cup supporting saidmagnet, and adjustable along it by reason of screw-threads, a diaphragmextending over the mouth of the cup, said cup having a peripheralflange,combined with a casing consisting of a body and a cap screwingthereonto, said peripheral flange extending between said cap and bodyand being clamped thereby, substantially as described.

3. ln a telephone-receiver, a casing consisting of a body and a capadapted to be secured directly thereto, a cup wit-hin the casingscrewing into the cap, whereby said cup is held by the casing andentirely inelosed within it, combined with a diaphragm between the cupand cap, and a magnet carried by the cup, substantially as described.

4f. In a telephone-receiver, acasing consisting of a body and a capscrewing directly thereonto by reason of internal threads on the cap andexternal threads on the body, a cup within the casing having a flangeextending between the cap and body and having screw threads on itsexterior, said screwthreads being adapted to form a continuation of thescrew-threads on the body whereby the same internal threading on the capmay mesh with both the cup and body, combined with a diaphragm betweenthe cup and cap, and a magnet carried by the cup, substantially asdescribed.

5. In a telephone-receiver, in combination, a cup having' a fiangescrew-threaded on its exterior and an opening through it screwthreadedon its interior, a horseshoe-magnet carrying a screw threaded blockengaging with said interior screw-threads whereby the cup adjustablysupports the magnet, a cap screwing onto said cup, a diaphragm betweensaid cap and cup, and a casing-body having external screw-threads andscrewing directly into said cap, whereby said cup is entirely inelosedwithin the cap and bodyand clamped thereby, substantially as described.

6. In a telephone-receiver, a pair of magnet-bars E, an insulating-blockM between the same, said block having an opening fm, a double flexiblecord dividing and passing onto opposite sides of said block and passingthrough the opening m in opposite directions,

electromagnets carried by said bars E, and

conductors leading therefrom to opposite sides of' said block and theresecured to the flexible cord, in combination with a diaphragm which saidmagnets are adapted to operate, and an insulating-casing inclosing theparts and having an opening through which the flexible cord extends,substantially as described.

7. In a telephone-receiver, the combination with a frame, a diaphragm incontact therewith, and a magnet carried by said frame, of a capdetachably secured to said frame and a shell detachably secured to saidcap, the cap and shell inclosing the other parts, substantially asdescribed.

8. In a telephone-receiver, the combination with a frame, a magnetadjustably mounted in said frame, and a diaphragm, of a cap detachablysecured to said frame and arranged to hold the diaphragm to the frame',and a shell detachably secured to the cap, substantially as described.

9. In a telephone-receiver, the combination with a frame, a magnetprovided with a head screw-threaded into the frame, and a diaphragm incontact with said frame, of a cap screw-threaded onto said frame andinclosing the diaphragm, and a shell screw-threaded onto the cap andinclosing the magnet, substantially as described.

lO. In a telephone-receiver, the combination with a hollow cone-frustumframe having an interior screw-threaded portion at its smaller end andan exterior threaded portion at the larger end, of a diaphragm incontact with the end surface of the large end of the frame, a magnetprovided with a magnethead having a screw-thread engaging the interiorscrew-threads in the magnet-frame, a cap provided with screw-threadsengaging the exterior screw-threads of the frame, and a shell inclosingthe magnet and provided with screw-threads engaging the cap,substantially as described. Y

ll. In a telephone-receiver, the combination with a frame, a magnethaving a head screwed partly into said frame, and a locknut on said headand arranged to engage the frame, of a diaphragm, a cap detachably se-IOO IIO

cured to the frame and inclosing the diaphragm, and a shell detachablysecured to the cap and inclosing the magnet and locknut, substantiallyas described.

l2. In a telephone-receiver, the combination, with a pair ofmagnet-legs, a diaphragm, coils, and means for holding said magnetlegs,coils and diaphragm in proper relation to each other, of a filling-piecebetween the ,legs of the magnet and provided with a trans-v verseopening, a pair of conductor-cords in electrical communication with therespective terminals of the coils, said conductor-cords being interlacedthrough the opening in the filling-piece, and a shell arranged toinclose the magnet, coils and lling-piece and provided with an openingthrough which the conductor-cords pass to the outside, substan. tiallyas described.

13. In a telephone-receiver, the combination with a magnet, coils anddiaphragm, and means for holding them in their proper relation to eachother, of binding-posts mounted in fixed relation to the coils andconnected to the terminals thereof, a pair of conductorcords, means formaking an electrical connection between the electrical conductors of theconductor-cords and the said vbindingposts, means for securing the conductor-cords to the receiver, and a shell inclosing the magnet, coils,binding-posts and securing means and provided with an opening throughwhich the conductor-cords extend, whereby the receiver may be suspendedfrom said cords Without straining the electrical conductors Within theconductor-cords or the binding-posts, substantially as described.

In testimony whereof I hereunto ax my signature in the presence of twowitnesses.

CHARLES NORTH.

Witnesses:

H. M. WISE, ALBERT H. BATES.

